<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <input type="text" v-model="info"><br>
  {{info}}<br>
  用户名: <input type="text" placeholder="输入用户名" v-model="user.username"><br>
  密码:<input type="password" placeholder="输入密码">

</div>
<!--引入vue框架-->
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
    let v= new Vue({
        el:"body>div",
        data:{
            info:"这是双向绑定测试",
          user:{
              username:"",
              password:""
          }
        }
    })
</script>
</body>
</html>